Your plants might be suffering from transplant shock. This happens when large plants are planted in the heat of the summer. Big leaf Hydrangeas (H. macrophylla) tend to wilt in the heat of the day even when well-established. The dogwood leaves may be curling due to a change in light intensity. If it was growing previously in morning light and is now in afternoon light (more intense), the leaves may just be sunburned. They will fall off and new leaves should emerge.

Wilting after planting can be due to the planting site, and how the plant was handled during and after planting. I could use some additional details. Please reply to this email so I receive your response.

1. What kind of soil do you have? Clay? Sand? Loam? Clay soil will hold water and suffocate roots, and sandy soil will drain quickly. Both cases can cause wilting. I am guessing because you are in WA county you have clay soil.
2. How big was the hole you dug? The recommendation is a hole about 2X the size of the rootball. Holes dug in clay soil just large enough for the rootball can make it hard for the roots to branch out.
   
3. Did you amend the soil with compost before placing the plant in the hole? Compost mixed well with clay soil helps improve drainage and creates air space for healthy root growth. Compost mixed with sandy soil will increase the water-holding capacity of the soil.
   
4. Did you purchase the plants from a nursery or did you get them from another person's yard (i.e. were they divisions / transplants you dug up yourself)?If you bought them from a nursery, they are likely potbound (see #5 below). If you dug them up from another site, they may have had root damage or poor root formation.
   
5. If the plants were potbound (roots tightly bound in the shape of the container), did you loosen the roots before planting? Did you use your fingers to gently loosen the roots or did you cut the roots with a tool? Cutting the roots may have caused some plant stress.
   
6. Have you watered the shrubs daily after planting? Feel the top six inches of soil in several places. If the soil is dry, water. More on water trees and shrubs: http://www.extension.umn.edu/garden/yard-garden/watering/#trees
   
7. What made you decide to apply a root stimulator? Were the roots poorly formed / sparse? What kind and how did you apply it? If the roots were healthy when you planted the shrubs, a root stimulator is not necessary.
   
8. What kinds of plants failed in this same location in prior years?
   
9. Would you also please send a picture that shows where each of these plants are planted (am looking for an idea of the site as a whole). Example: a plant could located near an air conditioning unit could be blasted with hot air when the unit is running, causing wilting. Or, a plant centered under an overflowing gutter could be pelted with rain which can create soil that is excessively wet and potentially could cause root rot.

TOday, I'm not concerned with the dogwood, it is looking a little less wilty. just the hydrangea. 
1.  We had a mixture of clay and sand, but I removed it and planted it with soil that they recommended at the nursery.  Cannot tell you what's in it, the bag is thrown away.  2.  The hole was about 1.5 times the size of the plant. There was no clay on the outsides of the hole, as far as I could tell.   3.  I totally amended the soil with brand new soil, using none of the old soil.
4.  Nursery.  5. The plant didn't seem rootbound.  I didn't break up at all. 6. I didnt' water daily, but the soil is testing very wet. 7.  thought i was supposed to put root stimulator in all new plants.  maybe this is the problem? 8.  THe plants were same (hydrangea replaced hydrangea, etc) 9. there's no a/c, no gutter

TOday, I'm not concerned with the dogwood, it is looking a little less wilty. just the hydrangea. 
1.  We had a mixture of clay and sand, but I removed it and planted it with soil that they recommended at the nursery.  Cannot tell you what's in it, the bag is thrown away.  2.  The hole was about 1.5 times the size of the plant. There was no clay on the outsides of the hole, as far as I could tell.   3.  I totally amended the soil with brand new soil, using none of the old soil.
4.  Nursery.  5. The plant didn't seem rootbound.  I didn't break up at all. 6. I didnt' water daily, but the soil is testing very wet. 7.  thought i was supposed to put root stimulator in all new plants.  maybe this is the problem? 8.  THe plants were same (hydrangea replaced hydrangea, etc) 9. there's no a/c, no gutter

It could still be wilted due to transplant shock and heat.

Hydrangeas require well-drained soil. Heavy wet soil can cause root rot which is exhibited by loss of leaves and wilting. If the soil is not draining well and is very wet, it can be causing the plant to wilt because the roots are not getting any air. Clay soil should be amended with compost. Adding sand to clay creates a very compacted soil - almost cement-like.

I would remove the plant, and examine the roots. If they are dark and mushy, they have been too wet. See if you can return it to the nursery and start with a healthy plant.

If the rootball very wet, but otherwise the plant roots are healthy and white, remove the sand / clay mixture (if possible) and amend the remaining soil with compost. Mix it into the soil really well. Loosen the roots of the hydrangea and replant. Water to settle in the soil. The plant may need some time to recover from being too wet. You may want to remove all or almost all the current flowers to lessen the support required by the plant. Let it re-bloom naturally.